Dividing cutting machine having means for rotating the jib arm

ABSTRACT

A bracket is rigidly connected to the frame of the machine. A swivel head is mounted in the bracket by radial and thrust bearing means for rotation about an axis of rotation. The radial and thrust bearing means comprise a radial bearing and also comprise thrust bearing means adapted to take up axial loads in opposite directions and having an effective diameter which exceeds the diameter of the radial bearing. A jib arm is mounted in the swivel head for rotation about a swivel axis which crosses the axis of rotation approximately at right angles.

United States Patent Sigott et al.

[ Aug. 12, 1975 [54] DIVIDING CUTTING MACHINE HAVING 2,327,928 8/1943 Osgood 299/72 MEANS FOR ROTATING THE JIB ARM 2,776,809 l/l957 Barrett 299/73 X $471,888 10/1969 Grant et al 299 70 X [75] Inventors: Siegfried Slgott; Hubert 3,661,274 5/1972 Woodside et a1. 212/68 Schwelberger, both of Zeltweg, Austria v Primary Examiner-Ernest R. Purser [73] Asslgneez Verermgte Osterrelchlsche Ersen- Attorney, Agent or pirm cushman, Dal-by &

und Stahlwerke Alpine Montan Cushman Aktiengesellschaft [22] Filed: June 28, 1973 [21] Appl. No.: 374,387 [57] ABSTRACT A bracket is rigidly connected to the frame of the ma- [30] Foreign Application priority Data chine. A swivel head is mounted in the bracket by ra- June w 197,) Ausmll 5647/7, dial and thrust bearing means for rotation about an i 7 7 axis of rotation. The radial and thrust bearing means comprise a radial bearing and also comprise thrust 2 1. 4 2 [5 l U S U 299/75 173/ 1 5 2 bearing means adapted to take up axial loads in oppo- [5 l 1 Int Cl 2 Ezlc 27/00 site directions and having an effective diameter which Fieid 75 7] 73 exceeds the diameter of the radial bearing. A jib arm 299/74 f 1 is mounted in the swivel head for rotation about a 4} ZM/ISI swivel axis which crosses the axis of rotation approximately at right angles.

[56] UNITE S SE FZ IF'ES SZiENTS 10 Claims, 2 Drawing Figures 2,284 677 6/1942 Osgood .1 299/72 I6 30 26 2/ 29 3O 3/ I I8" 11 r 6 1 1 I I8 '11 3e 11 1:

1 1 f 20 32 33 79 5'? 1 1 l 34 L 1 27-2& 24

I)IVIDING CUTTING MACHINE HAVING MEANS FOR ROTATING THE .IIB ARM BACKGROUND OF THE INVENTION In dividing cutting machines. the jib armis mounted on the frame of the machine for rotation in vertical and horizontal directions and can be rotated in these directions by a rotating mechanism. The cutting tool is mounted at the free end of the jib arm and must apply a high cutting pressure so that the jib arm is subjected to high stresses. The rotating mechanism which carries the jib arm must be designed to resist these high stresses. The conditions to which the rotating mechanism is subjected are rendered even more severe by the rough usage in a mine and by the development of dust. For this reason. the rotating mechanism of the known dividing cutting machines is subjected to heavy wear and liable to be deranged.

OBJECT AND SUMMARY OF THE INVENTION It is an object of the invention to eliminate this disadvantage. The invention relates to a rotating mechanism which comprises a swivel head. to which the jib arm is mounted for rotation in a vertical direction about a swivel axis. and a bracket. which is rigidly connected to the frame of the machine and on which the swivel head is mounted for rotation approximately in a horizontal direction about a preferably vertical axis of rotation which crosses the swivel axis approximately at right anglesv The invention resides essentially in that the swivel head is rotatably mounted by means of a radial bearing and by thrust bearing means which are adapted to take up the axial load in opposite directions and have an effective diameter which exceeds the diameter of the radial bearing. In this way. the load is shared by two bearings. Because the thrust bearing means can take up axial load in opposite directions. they will take up all vertical forces as well as the forces which tend to produce a tilting about a horizontal axis whereas only the forces which act in a horizontal direction must be taken up by the radial bearing. As a result. the weight of the pivoted jib arm. the reaction force which is due to the vertical rotation of said jib arm. and. where cutting tools are used which rotate about a horizontal axis which is transverse to the jib arm. also the cutting pressure are taken up by the thrust bearing means whereas the radial bearing is substantially loaded only by the reaction forces which are due to the rotation ofthe swivel head about its vertical axis of rotation. Because the effective diameter of the thrust bearing means exceeds the diameter of the radial bearing. higher stresses on the radial hearing are avoided since the tilting forces which are due to the jib arm are now taken up by the thrust bearing means on a large lever arm (effective di amctcr).

In accordance with the invention. the thrust bearing means comprise a plane bearing disc. which is guided between two sliding surfaces extending in parallel planes and which consists particularly of an annular disc whose inner and outer annular zones cooperate each with one of the two parts consisting of the swivel head and bracket. In a preferredembodiment of the invcntion. the arrangement is such that the inner annular zone of the annular bearing disc is rigidly connected to one of the two parts. preferably to the bracket. and the outer annular zone is disposed between and guided by sliding surfaces of the other of the two parts. preferably (ill the swivel head. Thus. the outer annular zone of the bearing disc acts as a thrust bearing and a relatively large effective diameter can be selected for said thrust bearing because in cutting machines of the kind under consideration an increase of the horizontal dimensions of the rotating mechanism can be more readily toleratcd than an increase of the vertical dimensions thereof as the overall height is limited. According to the invention. the outside diameter of the sliding surfaces of the bearing disc may be one-fourth to one-third of the largest overhang of the jib arm. measured from the axis of rotation of the swivel head to the center of the cutting tool.

In a desirable embodiment of the invention. the radial bearing is a self-aligning bearing which has a certain freedom of axial movement. As a result. this radial bearing takes up only horizontal forces and an axial clamping of the radial bearing which might result from manufacturing inaccuracies or from an axial backlash and which may cause a premature wear of the radial bearing is avoided.

The radial bearing consisting. e.g. of a self-aligning bearing. is suitably axially spaced from the bearing disc and close to a driving gear carried by the swivel head so that the radial bearing can directly take up the reaction forces which are due to the rotary movement imparted to the swivel head.

Because the bearing disc is large in diameter. a rugged mounting and a satisfactory taking up of the forces are ensured and a desirable embodiment of the invention is enabled. in which that portion of the swivel head which surrounds the bearing disc is disposed above and protrudes over the drive means. e. g. the hydraulic actuators. of the swivel and slewing drives. Such design will be of special advantage in view of the rough usage in a mine because all bearing parts are protected from dust. dirt. and water.

An embodiment of the invention is shown diagrammatically and by way of example of the accompanying drawing. in which BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing the rotating mechanism and FIG. 2 is a side elevation showing the dividing cutting machine.

DETAILED DESCRIPTION OF THE INVENTION A swivel head I is mounted in a bracket 2 for rotation about an approximately vertical axis of rotation 3. The bracket 2 is secured at 4 to a frame 5 of the dividing cutting machine. which is movable on endless tracks 6. A bridge 8 is mounted on the swivel head 1 for pivotal movement about an approximately horizontal swivel axis 7 and carries a jib arm 9. A rotating cutting tool II) is mounted on the free end of the jib arm 9 for rotation about a horizontal axis 1 I. The swivel head is provided at its other end with eyes 12. to which hydraulic actuators 15 are pivoted by a pivot I3. Pistons I4 of said actuators are connected by a pivot 16 to hearing eyes I7 of the bridge 8. These hydraulic actuators l5 serve to swivel the jib arm 9 about the horizontal axis 7.

An annular bearing disc 18 has an inner annular zone I8. which is rigidly connected by screws 19 to the bracket 2. An outer annular zone I8" of the disc I8 is disposed between and guided by bearing surfaces 20 and 21 of the swivel head I. A drive pinion 22 is axially spaced from the bearing disc 18 and is connected to the swivel head 1 by a torque-limiting clutch 23. Directly beside this pinion. a self-aligning bearing 24 is provided between the bracket 2 and the swivel head 1. A rack 25 is mounted in the bracket 2 and is in mesh with the pinion 22 to form the means for rotating the swivel head 1 so as to rotate the jib arm 9 in a horizontal direction. The rack 25 is operated by two single-acting hydraulic actuators. which are not shown.

The annular bearing disc 18 forms the thrust bearing and the self-aligning bearing 24 forms the radial bearing for the swivel head 1. The thrust bearing can take up a load in opposite axial directions because the annular disc 18 is disposed in the zone 18 between the two sliding surfaces 20 and 21 of the swivel head 1. As the radial bearing 24 takes up the radial forces. which are horizontally directed. the bearing disc 18 is relieved from such radial forces. For this reason. the sliding surfaces of the bearing disc 18 consists only of the parallel plane surfaces which cooperate with the sliding surfaces 20 and 21 whereas peripheral surface 26 has no bearing function and there may be a backlash at said peripheral surface. This bearing disc 18 takes up all vertically acting forces as well as the tilting forces acting about an imaginary horizontal axis. In theory. a

backlash at the sliding surfaces 20, 21 or an elastic deformation of the bearing disc 18 or the swivel head 1 might result in a pivotal movement about a horizontal axis extending through the radial bearing 24. To avoid damage to the bearing in this case. the radial bearing 24 consists of a selt aligning hearing. which has a certain freedom of movement also in the axial direction because its outer race 27 is axially movable in a turned aperture 28 formed in the bracket 2.

To insure a reliable mounting. the bearing disc is large in diameter. The outside diameter a is one-third to one-fourth of the largest overhang I; of the jib arm 9 measured from the axis of rotation 3 of the swivel head 1 to the center 11 of the cutting tool 10.

The inner annular zone 18 of the bearing disc 18 is connected to the bracket 2 on one side by the screws 19. On the top of the bearing disc 18. a gap 29 is defined by the zone 18 and the swivel head. and lubricating passages 30 open into said gap. This gap is sealed at the inner edge of the bearing disc 18 by a seal 31. The gap 32 between the swivel head 1 and the bracket 2 is also sealed by a seal 33 so that the sliding surfaces 20 and 21 are lubricated by the grease which is forced into the gap 29. A lubricating passage 34 is provided for the lubrication of the self-aligning bearing 24.

As is apparent from the drawing. the design is such that that portion 35 of the swivel head 1 which surrounds the bearing disc extends above and protrudes over the drive means consisting of the hydraulic actuators 15 and the slewing drive 22. 25. A rooflike extension 36 is also provided. All gaps 37 and 32 between the swivel head 1 and the bracket 2 extend downwardly from the thrust bearing which comprises the disc 18 so that the bearings are fully protected.

What we claim is:

1. A dividing cutting machine which comprises:

a frame.

a bracket rigidly connected to said frame.

a swivel head,

. separate radial and thrust bearing means by which said swivel head is mounted in said bracket for rotation about an approximately vertical axis of rota- 4 tion. said thrust bearing means for taking up only axial loads in opposite directions and having an effective diameter which exceeds the diameter ofthe radial bearing means. and said radial bearing means being spaced from said thrust bearing means in an axial direction,

c. said thrust bearing means including (i) a plane annular bearing disc having inner and outer annular zones. said bearing disc being rigidly connected on one side in said inner annular zone with one of the parts consisting of said bracket and swivel head. and (ii) two axially spaced apart confronting parallel plane sliding surfaces formed on the other of said parts consisting of said bracket and swivel head. said outer annular zone of said disc being disposed between and guided by said sliding surfaces, and

f. a jib arm which is mounted in said swivel head for rotation about a swivel axis which crosses said axis of rotation approximately at right angles.

2. The dividing cutting machine as set forth in claim 1. in which said radial bearing means is a self-aligning bearing.

3. The dividing cutting machine as set forth in claim 2. in which said radial bearing means is axially displaceable.

4. The dividing cutting machine as set forth in claim 1. in which said one of said parts is said bracket and said other of said parts is said swivel head.

5. A dividing cutting machine as recited in claim 1 wherein said jib arm has a free end opposite to said swivel head.

a cutting tool is mounted on said jib arm at said free end for rotation about a tool axis. and

said bearing disc has annular surfaces in sliding contact with one of the parts consisting of said bracket and said swivel head. said annular surfaces having an outside diameter which is one-fourth to one-third of the distance from said axis of rotation to said tool axis measured along said jib arm.

6. A dividing cutting machine as recited in claim 1 wherein said swivel head is provided with a drive gear. and

said radial bearing is axially spaced from said bearing disc and close to said drive gear.

7. A dividing cutting machine as recited in claim 1 wherein swivel drive means are connected to said jib arm to rotate the same about said swivel axis.

slewing drive means are connected to said swivel head to rotate the same about said axis of rotation.

and

said swivel head has a portion which surrounds said bearing disc and is disposed above and protrudes over said swivel drive means and slewing drive means.

8. The dividing cutting machine as set forth in claim 7. in which said swivel drive means comprise hydraulic actuator means.

9. The dividing cutting machine as set forth in claim 1. in which said bracket and said swivel heads define gaps between them and all said gaps defined by and between said bracket and swivel head extend downwardly from said thrust bearing means.

10. A dividing cutting machine comprising:

a frame a bracket rigidly connected to said frame.

. a swivel head. 7

. separate radial and thrust bearing means by which said swivel head is mounted in said bracket for rotation about an approximately vertical axis of rotation. said thrust bearing means for taking up only axial loads in opposite directions and having an effective diameter which exceeds the diameter of the radial bearing means, and said radial bearing means being spaced from said thrust bearing means in an axial direction.

. said thrust bearing means including (i) a plane annular bearing disc having inner and outer annular zones, said bearing disc being rigidly connected on one side in said inner annular zone with one of the parts consisting of said bracket and swivel head,

(ill

said inner annular zone defining. on a side opposite the side of said disc connected to one of the parts, a gap with the other of said parts, and wherein said parts define additional gaps between them, and wherein means are provided to seal said additional gaps and at least one lubricating channel leads to the said first mentioned gap, and (ii) two axially spaced apart confronting parallel plane sliding surfaces formed on the other of said parts consisting of said bracket and swivel head, said outer annular zone of said disc being disposed between and guided by said sliding surfaces, and

. ajib arm which is mounted in said swivel head for rotation about a swivel axis which crosses said axis of rotation approximately at right angles. 

1. A dividing cutting machine which comprises: a. a frame, b. a bracket rigidly connected to said frame, c. a swivel head, d. separate radial and thrust bearing means by which said swivel head is mounted in said bracket for rotation about an approximately vertical axis of rotation, said thrust bearing means for taking up only axial loads in opposite directions and having an effective diameter which exceeds the diameter of the radial bearing means, and said radial bearing means being spaced from said thrust bearing means in an axial direction, e. said thrust bearing means including (i) a plane annular bearing disc having inner and outer annular zones, said bearing disc being rigidly connected on one side in said inner annular zone with one of the parts consisting of said bracket and swivel head, and (ii) two axially spaceD apart confronting parallel plane sliding surfaces formed on the other of said parts consisting of said bracket and swivel head, said outer annular zone of said disc being disposed between and guided by said sliding surfaces, and f. a jib arm which is mounted in said swivel head for rotation about a swivel axis which crosses said axis of rotation approximately at right angles.
 2. The dividing cutting machine as set forth in claim 1, in which said radial bearing means is a self-aligning bearing.
 3. The dividing cutting machine as set forth in claim 2, in which said radial bearing means is axially displaceable.
 4. The dividing cutting machine as set forth in claim 1, in which said one of said parts is said bracket and said other of said parts is said swivel head.
 5. A dividing cutting machine as recited in claim 1 wherein said jib arm has a free end opposite to said swivel head, a cutting tool is mounted on said jib arm at said free end for rotation about a tool axis, and said bearing disc has annular surfaces in sliding contact with one of the parts consisting of said bracket and said swivel head, said annular surfaces having an outside diameter which is one-fourth to one-third of the distance from said axis of rotation to said tool axis measured along said jib arm.
 6. A dividing cutting machine as recited in claim 1 wherein said swivel head is provided with a drive gear, and said radial bearing is axially spaced from said bearing disc and close to said drive gear.
 7. A dividing cutting machine as recited in claim 1 wherein swivel drive means are connected to said jib arm to rotate the same about said swivel axis, slewing drive means are connected to said swivel head to rotate the same about said axis of rotation, and said swivel head has a portion which surrounds said bearing disc and is disposed above and protrudes over said swivel drive means and slewing drive means.
 8. The dividing cutting machine as set forth in claim 7, in which said swivel drive means comprise hydraulic actuator means.
 9. The dividing cutting machine as set forth in claim 1, in which said bracket and said swivel heads define gaps between them and all said gaps defined by and between said bracket and swivel head extend downwardly from said thrust bearing means.
 10. A dividing cutting machine comprising: a. a frame, b. a bracket rigidly connected to said frame, c. a swivel head, d. separate radial and thrust bearing means by which said swivel head is mounted in said bracket for rotation about an approximately vertical axis of rotation, said thrust bearing means for taking up only axial loads in opposite directions and having an effective diameter which exceeds the diameter of the radial bearing means, and said radial bearing means being spaced from said thrust bearing means in an axial direction, e. said thrust bearing means including (i) a plane annular bearing disc having inner and outer annular zones, said bearing disc being rigidly connected on one side in said inner annular zone with one of the parts consisting of said bracket and swivel head, said inner annular zone defining, on a side opposite the side of said disc connected to one of the parts, a gap with the other of said parts, and wherein said parts define additional gaps between them, and wherein means are provided to seal said additional gaps and at least one lubricating channel leads to the said first mentioned gap, and (ii) two axially spaced apart confronting parallel plane sliding surfaces formed on the other of said parts consisting of said bracket and swivel head, said outer annular zone of said disc being disposed between and guided by said sliding surfaces, and f. a jib arm which is mounted in said swivel head for rotation about a swivel axis which crosses said axis of rotation approximately at right angles. 